Telephone-transmitter



(No Model.) 2 Sheets-Sheet 1'. L. TOWNSEND.

TELEPHONE TRANSMITTER.

No. 348,430. Patented Aug. 31, 1886.

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(No Model.)

L. TOWNSEND.

TELEPHONE TRANSMITTER.

No. 348,430. Patented Aug. 31, 1886.

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UNITED STATES PATENT ()FFICE.

LOUIS TO\VNSEND, OF EVANSVILLE, INDIANA, ASSIGNOR OF ONE-HALF TO JOSEPH L. BAY AND WVILLIAM B. \VORTHEN, BOTH OF LITTLE ROCK,

ARKANSAS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 348,430, dated August 31, 1886.

(No model.)

To all whom, it may concern.-

Be it known that I, LOUIS TOWNSEND, of Evansville, in the county of Vanderburg and State of Indiana, have invented a new and Improved TelephoneTransmitter; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, making part of this specification, in which Figure 1 is a side elevation of the transmitter. Fig. 2 is a longitudinal sectional view on an enlarged scale. Fig. 3 is a plan view of the receiving end with the diaphragm and cap removed. Fig. 4 is a broken section showing the operation of the adjusting-screw. Fig. 5

is a view of a detail.

The object of my invention is to provide a telephonic transmitter having its vibratory contacts under the influence of a strong magnetic field, and red ace the liability of derangement from rough handling and consequent impairment of the utility of the instrument.

To this end my invention consists in certain novel elements and combinations and arrange- 2 5 ments of devices,as hereinafter fully described, and specifically pointed out in the claims.

In order that those skilled in the art may make and use my invention, I will proceed to describe the manner in which I have carried it out.

In the said drawings, A is a trumpet-shaped case, made of hard wood or any other desirable material, and hollowed out to receive an adjusting device and a vibratory contactpoint, as hereinafter set out. Inserted in the case at (L is one end of a short soft-iron tube, which may be made of a piece of gas-pipe seveu-eighths of an inch in diameter and five inches long. This soft-iron tube B forms the 40 core of an electro-magnct, completed by the helix 0, wound thereon, and proper electrical connections. \Vithin the end b of tube B,Where it passes into the case, is inserted a short metal plug, (1, forming a strong magnetic field. Flexibly secured within the case by means of a yielding plate, 6, and at right angles to the end I) of tube B, is an adjusting-bar, D, having in this instance one end curved slightly contact, E.

upward to form a bearing for an adjusting thumb -screw, f, while the opposite end is turned upward at right angles, as seen at g, and affords a bearing for one end of a highlyelastic steel spring, 71, which carries a carbon Firmly secured over the mouth of the case by means of screws 17 z is a dia phragm, made of ordinary sheet-tin, to the center of which is secured another contact-- point, E, the contacts E and E being in operative relation, and that relation susceptible of change by the changing of the position of the cross-bar D through the medium of the setscrew f. Over the end of the casing is fitted a cap, P, provided with a central opening, through which the sound-waves may pass.

- The instrument is connected by means of binding-posts t t t" t, the connections at posts t if being for the primary or battery connections, the wire from t terminating in a contact against the diaphragm, as seen at I, and the wire from post t being attached to the crossbar D, as seen at I. I wind the helix 0 to a resistance much higher than ordinarily given say about six hundred ohms in No. 36 wire.

Having thus described my invention, whatI claim as new, and desire to secure by Letters Patent, is

1. In a telephone, a tubular core, B, hav ing its end adjacent to the contacts closed, substantially as described, in combination with a helix, O, and proper electrical conuections,for the purpose specified.

2. The induction-coil and a proper casing, in combination with atransversc adj Listing-bar, spring 0, screw 1', electrical connections, and vibratory contacts, substantially as described. 8 5

3. The rigid diaphragm, provided with the contact E, in combination with the contact E, sustainingspring h, transverse adjustingbar D, flexibly secured to the case, the induction-coil B O, and proper electrical eonnecgo tions, all constructed, arranged, and operated as set forth.

LOUIS TOIVNSEND.

\Vitnesses:

J. W. NEXsEN, H. P. MONAIR. 

